Deodorization of lanolin and lanolin derivatives



United States Patent of New Jersey No Drawing. Filed June 14, 1963, Ser. No. 287,798

13 Claims. (Cl. 260-428) This invention relates to the deodorization of crude lanolin and lanolin derivatives, and particularly to a method of so processing lanolin and lanolin derivatives as to effect a substantially complete removal of odor therefrom. In a more specific aspect, the invention is concerned w th a method for the aforesaid purpose, wherein the material will at the same time be refined by the removal offree fatty acid, as well as water soluble oxidizable impurities, which may include peroxides, therefrom.

The term lanolin derivatives is hereinafter employed for the sake of brevity to mean and include lanolin, lanolin oil, lanolin absorption bases, wool wax alcohols, wool wax acids, lanolin wax fractions, ethoxylates of each of the foregoing, and esterified lanolins.

Lanolin derivatives generally contain offensive odors which have necessitated perfuming or masking when used by the formulator of various products in which a lanolin derivative is a constituent. These odors are especially objectionable when lanolin derivatives are employed in formulating relatively high priced materials such as cosmetics.

A particular objection to these odors is the fact that they are not consistently the same each time, but vary from batch to batch and from source to source, exhibiting many different offensive aromas.

As will be apparent, with all odors removed, the lanolin derivatives would be much better products, especially for use in the cosmetic trade.

Although present in minute amounts, odors in lanolln have required excessive perfuming in order to mask the same. Moreover, upon aging, most cosmetics containing lanolin derivatives, develop, even though perfumed, a heavy or musky smell characteristic of lanolin. If no odor is present to begin with, as in lanolin derivatives produced by the process of this invention, much more delicate'perfuming may be imparted to the lanolin-containing end products. It is, furthermore, an advantage to produce cosmetics containing fewer ingredients, by eliminating excessive masking ingredients normally required to overcome the animal odors of lanolin.

Heretofore, it has been the conventional practice to improve the odor and the color of lanolin by the means of bleaching clays and chemicals. Prior to thus treating the lanolin for improvement of odor and color, however, free fatty acids remaining therein must be removed. These free fatty acids derive from the wool grease and/or the scouring soaps used in washing the raw wool grease. customarily, the removal of these free fatty acids is achieved by alkali refining, utilizing alcoholic potash as a wash. In actual practice, it is found that between 2 and 6 pounds of lanolin ester is lost for each pound of free fatty acid removed. Obviously, this constitutes a large ester loss.

It is also known that lanolin derivatives contain water soluble oxidizable impurities which may include peroxides. These water soluble impurities are detrimental to lanolin derivatives, especially when formulated into creams or emulsions (ointments, etc.) containing sensitive active agents such as penicillin or other antibiotics. In such instances, the water soluble oxidizable impurities present in the lanolin derivative detrimentally affect and in certain cases completely destroy such active agents. On that ac- "ice count, those utilizing lanolin derivatives in such formulations desire that the same be of low water soluble oxidizable impurities content.

The principal object of the invention is to provide a process for treating lanolin derivatives whereby to effect a substantially complete removal of odors therefrom, quite independently of the source of the crude lanolin, and the variety or intensity of the odors.

Another object of the invention is to provide a process for the treatment of lanolin derivatives for the purpose aforesaid, and which will at the same time function, under appropriate operating conditions, to effect removal of free fatty acids therefrom, without loss of lanolin esters such as accompanies the alkali refining of lanolin.

Still another object of the invention is to provide a process as aforesaid, which will likewise function, under appropriate operating conditions, to effect removal of water soluble oxidizable impurities from the lanolin derivative's.

Still another object is to provide a process which will serve the foregoing purposes without degradation of the color of the treated material.

Briefly stated, the aforementioned objects of the invention may be achieved by subjecting the lanolin derivative, in the form of a relatively slowly moving whirling or socalled wiped film of relatively minute thickness, to contact with a heated surface while held under vacuum, and simultaneously subjecting the thus moving, heated film to the action of a countercurrent flow of steam or other inert gas.

In the practice of the invention, the aforementioned treatment of the lanolin derivative may be carried out in any suitable form of so-called wiped film evaporator. One suitable form of such evaporator preferably employed in the practice of the invention is that known as the Rodney Hunt Turba-film Evaporator. Other forms of such apparatus which may be utilized are those known as the Pfaudler Wiped Film Evaporator; the Luwa Thin Layer Evaporator; and the Kontro Evaporator.

In accordance with the invention, it has been found that by utilizing the principle of the so-called wiped film evaporator to impart an almost instantaneous heat increase to the deodorizable lanolin derivatives, and by simultaneously subjecting the whirling or wiped film to steam stripping while held under a high vacuum, substantially complete deodorization of the lanolin derivative may be effected under rather extreme conditions of high temperature and high vacuum without degradation of color and without destroying other valuable heat-destroyable properties of the lanolin derivative.

The Rodney Hunt Turba-film Evaporator referred to above, consists essentially of a jacketed vertical tube wherein rotating blades are arranged so as to operate with their peripheries in close proximity, i.e., of the order of thirty thousandths of an inch, to the heated jacket. The jacket may be heated by steam or Dowtherm. The liquid to be treated is whirled peripherally at a high rate, in the form of a film of relatively minute thickness, and is thus heated up very rapidly to the temperature of the inner wall of the jacket. The turbulent, whirling thin film created by the action of the rotor blades is centrifugally held in contact with the inner wall of the tube while flowing by gravity down through the tube to the outlet thereof. The liquid fed through the apparatus accordingly has a low residence time therein. This, together with the turbulent motion of the thin film prevent localized overheating.

It has been found that in the case of lanolin derivatives, the short time of contact, viz. about 10 seconds, between the whirling film and the heated surface of the tube, prevents any substantial darkening of the lanolin. At the same time, the extremely fast heat transfer heats up the feed liquid almost instantaneously. Furthermore, the whirling motion of the thin film of the lanolin derivative makes possible a very good contact of the lanolin derivative with the steam or other inert gas used as a stripping desirable for practical reasons. At or above the upper end of the aforementioned range, appropriate adjustment of the other operating factors may be necessary in order to avoid retention of some odor in some cases where the agent. Thus, when the whirling, heated, thin film of the 5 lanolin has a particularly bad odor to start with.

lanolin derivative, under the high vacuum maintained in The jacket temperature in these runs varied from 220 the tube, is contacted with steam or other inert gas flow- F. in certain cases to 545 F. in others.

ing countercurrently to the film, i.e., upwardly through The vacuum varied from 3 to 25 mm. Hg absolute presthe tube, deodorization by removal of all volatile material sure. Although satisfactory results were obtained with takes place. Shortly after the thus treated lanolin derivavacuum at the higher end of the aforementioned range of tive descends or slides down the wall of the tube, it is absolute pressure, operating at the lower end of said range collected at the bottom thereof and flows into a waterappears to be preferable. Although pressures lower than jacketed receiver from which it is pumped to drums. 3 mm. Hg absolute, may be utilized, this would require In the practice of the invention, the conditions of operapresently unavailable vacuum equipment capable not only tion may be varied considerably, depending upon the naof producing such low pressures, but also of handling the ture or constituency of the lanolin derivative to be procstripping steam utilized in accordance with the invention. essed, the nature and intensity of its odor, and its free fatty The rate of feed of the stripping steam varied from a acid content. Thus, the jacket temperatures may vary flow of approximately 3 pounds to approximately 30 from about 200 F. to about 600 F., and the product botpounds per 100 pounds of product per hour. toms temperature may range from about 190 F., to about As will be observed from the data in the foregoing 300 F. The vacuum utilized may vary from 0.5 mm. tables, lanolin derivatives having a variety of odors were Hg up to about 100 mm. Hg, preferably 3 to mm. Hg deodorized by the practice of the present invention, with absolute. The feed rate of the lanolin derivative may little, if any degradation of color. Moreover, depending vary from 5.0 to 70, preferably 8 to 50, pounds per hour upon the conditions of operation, the deodorization is per square foot of heating surface. The flow rate of 25 accompanied by reduction of the free fatty acid content stripping steam may vary from 0.1 to 10 pounds, preferof, as well as by removal of water soluble oxidizable imably 2 to 4 pounds steam per hour per square foot of heatpurities from, the lanolin derivative. ing surface, or from about 3 to about pounds per In general, it may be stated that the higher jacket tempounds of product. Reducing the flow of the stripping peratures tend to darken certain lanolin derivatives, while steam to 50% of the original rate (say from 3 pounds to 30 lower jacket temperatures do not completely remove odors 1.5 pounds per hour per square foot of heating surface) of certain lanolin derivatives, assuming other conditions does not appreciably affect the odor of the product. of operation remain constant.

In the following tables, there are set forth data with Further, it may be stated that so far as removal of free respect to various illustrative embodiments of the invenfatty acids is concerned, this is favored, generally speaktion. In each of these embodiments, the treatment of ing, by good steam rates, lower rates of feed and higher the lanolin derivative was effected in a Rodney Hunt jacket temperatures. Thus, for example, at jacket tem- Turba-film Evaporator having a heat transfer area of peratures of 250 F. to 350 F., little, if any, free fatty 4 square feet. acid is removed from lanolin (compare Runs 2 and 6).

TABLE A Feed Feed Jacket Bottoms Steam Odor Percent F.F.A. G.I'I. Color Run Rate, Temp Temp., Temp., Vacuum Rate, N0. #lhr. F. F. F. #lhr.

Feed Product Feed Prod. Feed Prod.

Acrid wool grease. 4. 0 33% 540 285 3.0 9.8 do Excellent 4.0 2.7 13-13% 4 -5 545 200 4.0 as 4.0 2.8 344% 4%-5 540 305 4. 0 9. s 4. 0 2. s 153% 4 M, 545 270 4. 5 0.8 Excellen 4.0 2.3 3-3% 4 2%) 220 245 22. 0 14. 0 Odor removed. 0.45 0. 30 8%4) sn-o 240 210 24.0 7. 0 Lot less 0. 40 0.38 8%9 8%9 350 220 25.0 7.0 do 0.40 0.42 saw-0 8%4) 505 240 5.0 11.2 No odor 0. 40 0. 33 8%4) 944-10 350 250 5.5 12.0 Low odor, 0. 54 0.44 8% 8%9 very good. 250 210 11.5 10.8 .do o 0. 54 0. 40 8% 310 225 4.0 14.1 do Odor removed. 0.34 0.38 8%9 8%-9 TABLE B [Feed0il fraction of lanolin derivative, known by the trade mark Lantrol] Feed Feed Jacket Bottoms Steam Odor Percent F.F.A. G.H.1 Color Run Rate, Temp., Temp, Temp, Vacuum Rate, No. #lllr. F. F. F. #0.

Food Product Feed Prod. Feed Prod.

so 220 500 250 3.5 0. 5a 0. 40 sx-o 0%40 220 495 290 4. 0 0. 53 0. 50 8%4) 941% 10s 220 505 205 4.0 0. 5a 0.54 8'A-9 8%4) 300 405 290 4.0 0.72 0.52 10 10%41 148 290 250 4.8 0. 52 0.58 8%4) 8%4;

! Gardner-Hellige.

As shown in the foregoing tables, feed rates of the material to be treated varied from 35 to 198 pounds per hour, resulting in a feed rate of from 8.75 to 49.5 pounds per hour per square foot of heat transfer area. Although feed rates substantially lower than the lower end of the Similarly, it may be stated that lower feed rates and higher jacket temperatures are most favorable to removal of water soluble oxidizable impurities. Moderate to good removal of water soluble oxidizable impurities is obtained at jacket temperatures of the order of 350 F., whereas aforementioned range would be operative, they are not as 75 only moderate to poor removal thereof is obtained in the range of 250 to 300 F. jacket temperature. It appears that for removal of Water soluble oxidizable impurities from lanolin derivatives, the conditions of vacuum and steam stripping are not as significant as are the time of contact and the jacket temperature.

Referring to Table A, and specifically to Runs Nos. 1

to 4, in which the feed material was a crude lanolin having an odor of acrid Wool grease (resembling that of aged lanolin) and a relatively high free fatty acid content (4.0%), it will be noted that the deodorization thereof by treatment in accordance with the invention was accompanied by a substantial reduction in the free fatty acid content, though with some darkening of color. In Runs Nos. 5 to 11, wherein the feed materials were various lanolins having varying odors and a relatively low content of free fatty :acid (varying from 0.40% to 0.54%) the deodorization results shown in the table were accompanied by some reduction of free fatty acid condent, particularly in those of the runs conducted at higher jacket temperatures and higher vacuum. As shown by the data, avoidance of darkening of color is favored by utilizing lower jacket temperatures.

Although most of the runs in Table A were conducted at a vacuum of 3.0 to about 6.0 mm. Hg, it will be noted that satisfactory deodorization was obtained in Runs No. 5, 6, 7 and 10, conducted at substantially higher pressure (i.e., vacuum of 11.5 to 25.0 mm. Hg).

Referring to Table B, in which the feed materials were ethoxylated lanolins having pungent or very strong odors, the data shown therein demonstrates that these materials may be deodorized by the practice of the invention. Although most of these runs were conducted at jacket temperatures of the order of 500 F. it appears that with the feed materials there utilized, quite efficient deodorization thereof may be effected at jacket temperatures in the range of 250 F. to 350 F., with the additional advantage of less darkening of color of the product, compared to that which manifests itself when operating at the jacket temperatures in the region of 500 F. or above.

It has been pointed out above that in the refining of Wool grease to produce lanolin, one of the troublesome problems is the removal of free fatty acids to leave an amount below 0.56% in order to bring the product within the U.S.P. range. Normally, the EPA. content of crude wool grease varies from 2% to As shown by Runs Nos. 1 to 4, Table A, the F.F.A. content was reduced to the order of 2.3% to 2.8% under the conditions utilized therein for the deodorization, the greater reduction being attained at the lower rates of feed. Thus, since normally 4 to 6 pounds of lanolin are lost or degraded for each pound F.F.A. removed in the alkali refining, the loss of lanolin alkali refining the product of Runs Nos. 1 to 4 would be considerably less than normally encountered in alkali refining of wool grease having an initial F.F.A. content of 4%. Although an even more complete removal of F.F.A. from wool grease can be effected at still higher jacket temperatures, it appears that this would entail more extensive darkening of the wool grease than that incurred in Runs Nos. 1 to 4.

The F.F.A. content of others of the feed materials referred to in the tables was in the range of 0.4% to 0.72%, and the conditions of operation utilized for deodorization in most instances also effected a reduction of the REA. content to bring the latter well down within the U.S.P. range.

Thus, whereas normally the heating of lanolin derivatives to temperatures above 180 F. for one-half hour or longer readily brings about a rise in the F.F.A. content to a value above the U.S.P. range, the present invention provides a process whereby the lanolin derivatives may be deodorized while simultaneously reducing the F.F.A. content thereof.

Reference has hereinabove been made to the presence of water soluble oxidizable impurities in lanolin derivatives, and to the detrimental effect thereof especially when formulated into products containing sensitive active agents, such as penicillin. It is difficult to remove these water soluble oxidizable impurities from lanolin derivatives by known methods. It has been found, however, that in deodorizing lanolin or lanolin derivatives in accordance with the present invention, a substantial part, if not all, of the water soluble oxidizable impurities con tent is removed.

The test used to determine the presence of water soluble oxidizable impurities in lanolin derivatives is based upon the effect of adding 0.05 ml. of a 0.1 normal solution of potassium permanganate to a 10 ml. portion of the water layer separated from the lanolin derivative when 10 grams of the latter have been warmed with 50 .grams of water under constant stirring and then cooled until the water layer is clear. When the permanganate solution is first added to the solution to be tested, the latter takes on a pink color. If the lanolin derivative is completely free of water soluble oxidizable impurities, the pink color remains for 10 minutes; if some water soluble oxidizable impurities are present, the pink color gradually fades or completely disappears, depending upon how much water soluble oxidizable impurities are present.

As determined by the foregoing test, the extent of removal of residual water soluble oxidizable impurities during deodorization of the lanolin derivatives according to the runs set forth in Tables A and B is shown in the following table:

TABLE C.TEST RESULTS Feed Products Pink gone in 2 min SI. pink after 10 min.

do .1 V. sl pink after 10 min.

The test results shown in Table C indicate that removal of most Water soluble oxidizable impurities is favored when the deodorization is conducted at lower feed rates and higher jacket temperatures.

From all of the foregoing, it will be evident that the process of the invention is an efi icaceous one for deodorizing lanolin derivatives without substantial degradation of color, and for simultaneously (1) removing free fatty acids, especially when operating at lower feed rates, higher jacket temperatures, higher vacuum and good steam rates, and (2) removing water soluble oxidizable impurities especially when operating at lower feed rates and higher jacket temperatures.

What is claimed is:

1. A process for deodorizing a lanolin material selected from the group consisting of lanolin, lanolin oil, wool Wax alcohols, lanolin wax fractions, ethoxylatcs of each of the foregoing, and esterified lanolins, which comprises continuously feeding said lanolin material into contact with the inner wall of a heated jacket, causing the feed material to fiow downwardly along the surface of said wall to be heated thereby while in the form of a wiped film of relatively minute thickness, said film being formed by a wiping action which imparts turbulence to said film and causes it to spiral as it flows downwardly along said surface, subjecting said film to a vacuum in the range of from 0.5 to mm. mercury absolute while thus heated, and simultaneously subjecting the thus heated film to the action of a countercurrent flow of steam.

2. A process as defined in claim 1, wherein said surface is heated to a temperature in the range of 200 F. to 600 F.

3. A process as defined in claim 2, wherein said tem perature is in the range of about 215 F. to about 500 F.

4. A process as defined in claim 1, wherein the vacuum utilized is in the range of from about 3 mm. Hg to about 25 mm. Hg absolute.

5. A process as defined in claim 1, wherein said lanolin material is heated to a temperature in the range of from about 190 F. to about 300 F.

6. A process as defined in claim 1, wherein the steam flow is at a rate of from 0.1 pound to 10 pounds per hour per square foot of said surface.

7. A process as defined in claim 1, wherein the steam flow is at a rate of from about 3 to about 30 pounds per 100 pounds of said lanolin material passed over said surface.

8. A process as defined in claim 1, wherein the feed rate of said lanolin material is between about 5.0 and 70 pounds per hour per square foot of said heated surface.

9. A process as defined in claim 1, wherein the feed rate of said lanolin material is between 8 and 50 pounds per hour per square foot of said heated surface.

10. A process for deodorizing a lanolin material selected from the group consisting of lanolin, lanolin oil, wool wax alcohols, lanolin wax fractions, ethoxylates of each of the foregoing, and esterified lanolins, which comprises continuously passing said lanolin material in wiped film form over a heated surface at a rate between about 8 and about 50 pounds per square foot of said heated surface while said surface is heated to a temperature in the range of about 215 F. to about 500 F. and while holding said film under a vacuum in the range of 0.5 to 100 mm. Hg absolute, and simultaneously subjecting said film to the action of steam flowing countercurrent to said film at a rate of from 0.1 to 10 pounds per hour per square foot of said heated surface.

11. A process as defined in claim 10, wherein the rate of feed of said lanolin material, the jacket temperature and the rate of steam flow are each respectively selected from within said ranges thereof so as to effect removal of free fatty acids from said lanolin material during the deodorization thereof.

12. A process as defined in claim 10, wherein the rate of feed of said lanolin material and the jacket temperature are each respectively selected from within said ranges thereof so as to effect removal of water soluble oxidizable impurities from said lanolin material during the deodorization thereof.

13. A process as defined in claim 11, wherein the selected rate of feed of said lanolin material, the selected jacket temperature and the selected rate of steam flow are effective to simultaneously remove water soluble oxidizable impurities from said lanolin material during the deodorization thereof.

References Cited by the Examiner UNITED STATES PATENTS 6/1924 La Bour 260428 3/1927 Wecker 260428 

1. A PROCESS FOR DEODORIZING A LANOLIN MATERIAL SELECTED FROM THE GROUP CONSISTING OF LANOLIN, LANOLIN OIL, WOOL WAX ALCOHOLS, LANOLIN WAX FRACTIONS, ETHOXYLATES OF EACH OF THE FOREGOING, AND ESTERIFIED LANOLINS, WHICH COMPRISES CONTINUOUSLY FEEDING SAID LANOLIN MATERIAL INTO CONTACT WITH THE INNER WALL OF A HEATED JACKET, CAUSING THE FEED MATERIAL TO FLOW DOWNWARDLY ALONG THE SURFACE OF SAID WALL TO BE HEATED THEREBY WHILE IN THE FORM OF A WIPED FILM OF RELATIVELY MINUTE THICKNESS, SAID FILM BEING FORMED BY A WIPING ACTION WHICH IMPARTS TURBULENCE TO SAID FILM AND CAUSES IT TO SPIRAL AS ITS FLOWS DOWNWARDLY ALONG SAID SURFACE, SUBJECTING SAID FILM TO A VACUUM IN THE RANGE OF FROM 0.5 TO 100 MM. MERCURY ABSOLUTE WHILE THUS HEATED, AND SIMULTANEOUSLY SUBJECTING THE THUS HEATED FILM TO THE ACTION OF A COUNTERCURRENT FLOW OF STEAM. 